<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    div {
        width: 749px;
        background-color: red;
        /* font-size: 0px; */


        /* display: flex;
        flex-direction: column; */




    }

    div img {
        display: block;
    }
</style>

<body>
    <div>
        <img src="http://img5.gomein.net.cn/image/prodimg/productDesc/descImg/201410/desc7730/9133093178/9131870369_02.jpg"
            alt=""><img
            src="http://img5.gomein.net.cn/image/prodimg/productDesc/descImg/201410/desc7730/9133093178/9131870369_04.jpg"
            alt=""><img
            src="http://img5.gomein.net.cn/image/prodimg/productDesc/descImg/201410/desc7730/9133093178/9131870369_07.jpg"
            alt="">
    </div>
</body>
<script>

    var str = `
    td>
				<img width="750" height="166" class="gomeImgLoad" alt="" src="http://img5.gomein.net.cn/image/prodimg/productDesc/descImg/201404/desc6284/9123820115/1_39.jpg" />
			</td>
    td>
				<img width="749" height="166" class="gomeImgLoad" alt="" src="http://img5.gomein.net.cn/image/prodimg/productDesc/descImg/201404/desc6284/9123820115/1_39.jpg" />
			</td>
            `

    //  \d 匹配所有数组
    var reg = /width="\d*"/g


    console.log(str.replace(reg, `width="100%"`));


</script>

</html>